Selecting a semi-persistent scheduling interval for grant-free wireless devices

Abstract

According to certain embodiments, a method by a network node for selecting a semi-persistent scheduling (SPS) interval for a wireless device in a cell served by the network node includes determining criterion for selecting the SPS interval for the wireless device. The criterion is associated with at least one of a QoS requirement of the wireless device and a utilization of resources by the network node. The network node assigns the SPS interval to the wireless device based on the criterion.

The invention claimed is: 
     
       1. A method by a network node for selecting a semi-persistent scheduling (SPS) interval for a wireless device in a cell served by the network node, the method comprising:
 determining criterion for selecting the SPS interval for the wireless device, the criterion being associated with at least one of: 
 a QoS requirement of the wireless device; and 
 a utilization of resources by the network node; and 
 assigning the SPS interval to the wireless device based on the criterion. 
 
     
     
       2. The method of  claim 1 , wherein:
 the criterion is associated with a priority of the wireless device, and 
 the SPS interval is assigned based on the priority of the wireless device. 
 
     
     
       3. The method of  claim 2 , further comprising determining whether the wireless device is a VIP wireless device, and wherein assigning the SPS interval comprises:
 assigning a shorter SPS interval if the wireless device is a VIP wireless device; and 
 assigning a longer SPS interval if the wireless device is not a VIP wireless device. 
 
     
     
       4. The method of  claim 3 , wherein the shorter SPS interval is for a time interval of 1 ms. 
     
     
       5. The method of  claim 2 , further comprising determining the priority of the wireless device based on a subscriber profile identifier associated with a user of the wireless device. 
     
     
       6. The method of  claim 1 , wherein the criterion is associated with a Quality of Service Class Identifier (QCI), and the method further comprises determining at least one QCI associated with the wireless device, and wherein assigning the SPS interval to the wireless device comprises assigning the SPS interval based on the at least one QCI associated with the wireless device. 
     
     
       7. The method of  claim 6 , wherein:
 a plurality of QCIs are associated with the wireless device, 
 each of the plurality of QCIs are associated with a respective one of a plurality of SPS intervals, and 
 assigning the SPS interval comprises selecting a SPS interval from the plurality of SPS intervals that corresponds to a particular one of the plurality of QCIs with a highest priority. 
 
     
     
       8. The method of  claim 1 , wherein the criterion is associated with the utilization of resources by the network node, and the method further comprises monitoring system resources during a measurement window to determine a measure of available resources in the cell, and wherein assigning the SPS interval to the wireless device comprises assigning the SPS interval based on the measure of available resources in the cell. 
     
     
       9. The method of  claim 8 , wherein monitoring system resources comprises:
 determining an actual amount of resources utilized by all wireless devices scheduled in the cell during a transmission time interval; and 
 filtering the actual amount of resources utilized by all wireless devices scheduled in the cell during the transmission time interval over the measurement window, wherein the measurement window comprises one or more transmission time intervals. 
 
     
     
       10. The method of  claim 8 , further comprising:
 comparing a measure of the actual amount of resources utilized by all wireless devices scheduled in the cell during the transmission time interval as filtered over the measurement window to a threshold; 
 if the measure of the actual amount of resources utilized by all wireless devices scheduled in the cell during the transmission time interval as filtered over the measurement window is less than a threshold, selecting a first SPS interval; and 
 if the measure of the actual amount of resources utilized by all wireless devices scheduled in the cell during the transmission time interval as filtered over the measurement window is not less than the threshold, selecting a second SPS interval. 
 
     
     
       11. The method of  claim 8 , further comprising:
 comparing the measure of available resources in the cell to a plurality of thresholds, each of the plurality of thresholds being associated with a selected one of a plurality of SPS intervals, and wherein a shorter SPS interval is associated with a lowest threshold and a longer SPS interval is associated with a highest threshold. 
 
     
     
       12. The method of  claim 1 , further comprising:
 determining that the QoS requirements of the wireless device or the utilization of resources by the network node has changed since the assignment of the SPS interval; and 
 adjusting the SPS interval for the wireless device in response to determining that the at least one of the QoS requirement of the wireless device or the utilization of resources by the network node has changed. 
 
     
     
       13. A method implemented in a communication system including a host computer, a base station and a user equipment (UE), the method comprising:
 at the host computer, providing user data; and 
 at the host computer, initiating a transmission carrying the user data to the UE via a cellular network comprising the base station, wherein the base station performs 
 determining criterion for selecting the SPS interval for the UE, the criterion being associated with at least one of: 
 a QoS requirement of the UE; and 
 a utilization of resources by the base station; and 
 assigning the SPS interval to the UE based on the criterion. 
 
     
     
       14. A network node for selecting a semi-persistent scheduling (SPS) interval for a wireless device in a cell served by the network node, the method comprising:
 a memory storing instructions; and 
 processing circuitry configured to execute the instructions to cause the network node to: 
 determine criterion for selecting the SPS interval for the wireless device, the criterion being associated with at least one of: 
 a QoS requirement of the wireless device; and 
 a utilization of resources by the network node; and 
 assign the SPS interval to the wireless device based on the criterion. 
 
     
     
       15. A communication system including a host computer comprising:
 processing circuitry configured to provide user data; and 
 a communication interface configured to forward the user data to a cellular network for transmission to a user equipment (UE), 
 wherein the cellular network comprises a base station having a radio interface and processing circuitry, the base station's processing circuitry configured to: 
 determine criterion for selecting the SPS interval for the UE, the criterion being associated with at least one of: 
 a QoS requirement of the UE; and 
 a utilization of resources by the base station; and 
 assign the SPS interval to the UE based on the criterion.